Now that I'm back, I can elaborate
Just through teleportation, Left was able to completely evade the hits of CiC, circling around and generally dominating the fight without them getting a single touch in, as that would activate the powers of the red universe and put left entirely under his mind control. Heck, he did that a multitude of times across their fights in the past, and Left only ever lost ground thanks to the CiCdrome forcibly controlling the entirety of YouTube and firing off 8-A attacks, to which Left had to just retreat
While I think I remember Left failing to teleport giant opponents (thus preventing him from doing his usual strategy of just clocking someone in the face, teleporting them into the air and forcing them into freefall where they're completely helpless and have to re-orient, only to be punched again), he can still just engage point blank. The eyes and eardrums are way less durable than someone's ribcage or skull, so a single solid punch from someone at least comparable in strength is liable to completely take out both of those senses
Without their sense of hearing to give them equilibrium, their giant size is going to become even more of a disadvantage as they'll be unable to really gain their balance, which would really drill in Left's ability to reliably just dodge around and get hits in.
Sonic isn't particularly skilled and even the spindash is something with windup that Left can just teleport away from, so it's kinda a clear cut David vs Goliath